Comments

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
In "usb/uas: use unique tags for all LUNs" we make sure to create unique
tags across all LUNs. This patch uses scsi_host_find_tag() to obtain the
correct command which is associated with the tag.
The following changes are required:
- don't use sdev->current_cmnd anymore
Since we can have devices which don't support command queueing we must
ensure that we can tell the two commands apart. Even if a device
supports comand queuing we send the INQUIRY command "untagged" for
LUN1 while we can send a tagged command to LUN0 at the same time.
devinfo->cmnd is used for stashing the one "untagged" command.
- tag number is altered. If stream support is used then the tag number
must match the stream number. Therefore we can't use tag 0 and must
start at tag 1.
In case we have untagged commands (at least the first command) we must
be able to distinguish between command tag 0 (which becomes 1) and
untagged command (which becomes curently also 1).
The following tag numbers are used:
0: never
1: for untagged commands (devinfo->cmnd)
2+: tagged commands.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
drivers/usb/storage/uas.c | 33 +++++++++++++++++----------------
1 file changed, 17 insertions(+), 16 deletions(-)